title: 2-Hy-droxy-iso-quinoline-1,3(2H,4H)-dione.
abstract: The title mol-ecule, C9H7NO3, exists in the diketo form and the iso-quinoline unit is approximately planar (r.m.s. deviation = 0.0158 Å). In the crystal, mol-ecules are linked into inversion dimers through pairs of O-H⋯O hydrogen bonds and are further assembled into the (100) layers via stacking inter-actions [centroid-centroid distances = 3.460 (3) and 3.635 (4) Å].
authors.affiliation: School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Ishikawa
authors.forename: Soichiro
authors.initials: S
authors.lastname: Matsuo